Applying measured unsaturated hydraulic conductivity to estimate pore-size distribution of porous media
Abstract
The growth and activity of animals and plants in the soil, even earthquakes and environmental exploitation, will cause numerous cracks to be scattered inside soil. The current techniques for investigating pore-size distribution are mostly limited to the laboratory. The long-term observation of the changes in pore-size distribution in field is still a challenge. Based on the relationship between water movement in unsaturated soil and its pore-size distribution, we proposed a method for pore-size distribution estimation and the observation of soil profile in the field. This study derived two equations to describe the relationship between pore radius (r) and unsaturated hydraulic conductivity (K) in one-dimensional vertical flow. The root mean square error (RMSE) between the estimated unsaturated hydraulic conductivities from the proposed equations with the known pore radii and the measured ones were 0.508 and 0.553, respectively. Furthermore, the range of unsaturated hydraulic conductivity was measured by the soil column experiments and used to estimate the corresponding pore radii with the proposed equations. With the distribution of these pore radii, the pore-size distribution in the soil profile was estimated. Finally, the pore-size distribution at different depths of 5 cm and 13 cm in the soil profile were displayed. Therefore, we concluded that the proposed method can be applied to estimate the pore-size distribution in soil profile with different depths. Further, it can also be applied to the prediction of the dominant path of groundwater exchange, the potential path of pollutants, sewage in soil, and the soil structure weakening on the hillside.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H53N1976T
- Keywords:
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- 1843 Land/atmosphere interactions;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY;
- 1865 Soils;
- HYDROLOGY;
- 1875 Vadose zone;
- HYDROLOGY